61721214001225 has 81 divisors (see below), whose sum is σ = 79218567019893. Its totient is φ = 47703362520000.

The previous prime is 61721214001217. The next prime is 61721214001229. The reversal of 61721214001225 is 52210041212716.

The square root of 61721214001225 is 7856285.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 11396491505161 + 50324722496064 = 3375869^2 + 7093992^2 .

It is not a de Polignac number, because 61721214001225 - 2³ = 61721214001217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61721214001229) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 186468924310 + ... + 186468924640.

Almost surely, 2^{61721214001225} is an apocalyptic number.

61721214001225 is the 7856285-th square number.

61721214001225 is the 3928143-rd centered octagonal number.

It is an amenable number.

61721214001225 is a deficient number, since it is larger than the sum of its proper divisors (17497353018668).

61721214001225 is an frugal number, since it uses more digits than its factorization.

61721214001225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 968 (or 484 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 34.

The spelling of 61721214001225 in words is "sixty-one trillion, seven hundred twenty-one billion, two hundred fourteen million, one thousand, two hundred twenty-five".